1. Technical Field of the Invention
This invention relates to an educational toy and, in particular to constructional toys which can be interconnected.
2. Description of the Prior Art
There have been many different forms of educational toys which are known generally as constructional toys in which the various components connect together.
Some of these, and the ones to which this invention relate are basically in the form of flat members which may have various shapes, such as triangles, squares, pentagons etc. and which are connected together by complimentary portions along adjacent edges.
One well known toy of this type is sold under the registered trade mark "Polydron". The Polydron toy has along its length one portion which extends outwardly to a notional periphery of the side and a portion which is located inwardly of this, the outwardly directed portion having a cut away portion adjacent its outer edge and the inward portion having an outwardly extending portion on its outer edge, the inward edge portion being effectively in line with the inward portion of the edge and the outward end portion being effectively in line with the outward portion.
In the Polydron toy at the junction of the two portions there is a spring member which is formed of the same material as the body of the toy and defined by two cut outs directed towards the centre of the toy.
The portions are formed with a pip on the outer edge of the outwardly directed portion and a dimple on the outwardly directed end portion adjacent the inward portion so that when two like members are engaged but are inverted one relative to the other, the pips and dimples engage and there is a resilient outward pressure provided by the spring members which are in contact with each other.
It will be seen that the two members so inter-engaged are effectively pivotally connected to each other and by proper relationship with other members, structural members can be produced.
The Polydron toy, whilst satisfactory has a number of disadvantages.
First of these is that the spring members are put under stress when adjacent members are interconnected and they can well break and, once, one of these members is broken, there is no pressure put on the junction between the pips and dimples and the components do not hold together.
The second is that where the members are solid it can be difficult to construct a complex shape as the building of the shape has to all be done from effectively the outer surface. A further disadvantage is that the members are relatively expensive in that they are formed from solid plastics material and the quantity of plastics in each component is relatively high.